Behind every American coming-of-age story stands a single passage, in which George Willard, Sherwood Anderson's alter-ego, sits in a carriage of the B&O railroad, waiting to leave Winesburg, Ohio:

The young man, going out of his town to meet the adventure of life, began to think but he did not think of anything very big or dramatic. Things like his mother's death, his departure from Winesburg, the uncertainty of his future life in the city, did not come to mind. He thought of little things -- Turk Smollet wheeling boards through the main street of his town in the morning, a tall woman, beautifully gowned, who had once stayed overnight at his father's hotel, Butch Wheeler the lamp lighter of Winesburg hurrying through the streets on a summer evening and holding a torch in his hand, Helen White standing by a window in the Winesburg post office and putting a stamp on an envelope. The young man's mind was carried away by his growing passion for dreams. One looking at him would not have thought him particularly sharp. With the recollection of little things occupying his mind he closed his eyes and leaned back in the car seat. He stayed that way for a long time and when he aroused himself and again looked out the car window the town of Winesburg had disappeared and his life there had become but a background on which to paint the dreams of his manhood.

Is such escape still possible? Or does Facebook and other social networking sites that reconnect you to the librarians and lamplighters of your own personal Winesburg, Ohio, make getting away a fantasy? We're all swamped by the effluvia of our junior varsity selves now. The whistle blows, the car rattles, but it's always the same town outside the same window.

"Winesburg, Ohio" is a founding text of the coming-of-age genre, but I prefer to think of it simply as writing to get back what you lost, all those lamp-lit evenings when Helen White followed you through Hern's Grocery store -- an earlier time in your life but also an earlier time in the life of the republic. The railroad that carried you away runs through your story like a bottom line. It is where God transferred the short-term memories into the safer, long-term memory banks.

To me, the above passage is more than Anderson's lyrical exit from his novel; it's an admonition to strike out for new territory. Here's what he is saying: As your ancestors crowded into ships that took them over the sea, you must crowd into Hondas and Toyotas, hatchbacks full of luggage, brains packed with memories, and go away from your land to possess your land.

This notion of the writer as someone who must lose his friends to preserve his friends, or have them back in another way, echoes from Anderson to Hemingway to Naipaul: Hemingway, who had to move to Paris to write about Michigan; Naipaul, who had to move to London to write about Port of Spain.

In the last couple of years, however, the geometry of this transaction has changed. For those plugged into Facebook -- and this is more and more of us -- there simply is no getting away. Perhaps you first signed onto the site as the hero of Celine's "Journey to the End of the Night" signed on with the army, in an air of holiday amusement, to see what it was all about, only to find yourself returned to the past as a disobedient dog is forcibly returned to the scene of his accident. Photos, updates, friend requests: This arcanum rises above you like a wave, a tremendous roller that flashes for a moment before soaking you in junk and debris you believed had been left behind.

For this reason, a kind of reminiscence -- a tone, really, a sense of "Goodbye to all that" -- must soon vanish from our literature.

First, there is the simple matter of safety. To write about kids from, say, Central School, Glencoe, Ill., circa 1982, you need the illusion that you have left that party and gone on to another, better party, where you can trash your old friends without fear of consequence. They can't hear you, can't reach you, don't even know where you are. I mean, when you write such a book, what are you doing if not talking behind the back of an entire town?

You're a boll weevil, an eavesdropper, a diary reader, a secret stealer, a dirty rat.

A writer should be judged by how honest and brutal he will be: by the quality of the secrets he tells, as well as by the panache with which he tells them. It's what Czeslaw Milosz meant when he said, "When a writer is born into a family, that family is finished."

A few years ago, the New York Times ran a story in which a reporter visited Traverse City, in the Upper Peninsula of Michigan, where Hemingway set his first stories. The people of the town, all those years later, the very old ones, were still angry with Hemingway, for the confidences he violated, for the way he distorted, for how he got it all wrong. He wrote as if the people in Traverse City had died, as if Michigan were gone, as if there were no one left to look over his shoulder or complain.

The past is another country, that's how someone put it. (It was another country; there has since been an Anschluss.) Hemingway had to leave Michigan to write about Michigan. By writing about Michigan, he made return to Michigan impossible. By writing about Michigan, he both destroyed and preserved Michigan.

It's a Faustian bargain. He got it and lost it. But if he were publishing today and was on Facebook -- and I am sure he would be, as Hemingway wanted to taste everything -- he would be flooded with friend requests, each accompanied by a comment:

Ernest . . . I will have you know Mr. and Mrs. Eliot are now expecting their second child. Check your facts!

Ernie . . . Krebs was fine when he got back, and is fine now. Maybe you were confusing him with Clay, who is nuts, but was never in the army.

Ernest . . . As far as I'm concerned, we never were dating, so I'm not sure how you are certain you could get me back.

Facebook, with its flow of useless particularity, makes it impossible to forget, thus impossible to remember. Memory is really the story left behind by forgetting -- the essence that remains when the years have stripped away all that useless particularity. You remember as much by forgetting as you do by remembering. But on Facebook, the past becomes the wound that is never allowed to heal so never scars into deep experience.

The Buddhists say do not describe the water until the mud has settled and you can see its true essence, but the mud never does settle online. The water is continually stirred up, making remembering impossible. The memory in your mind is replaced by a detail posted on a Web page, which may be more accurate but is probably less true. Gone is the friend you knew from home. Gone is the sled and the lake and the winter. Gone are the stories that existed in the gap between imagining and knowing and, with them, the distance that turned the particular into the universal and the mundane into the romantic.

In this way, the past, seeming to get closer, actually gets further away. In this way, even the most daring of us become cutters, spending our lives on the streets of Winesburg. In this way, Helen White writes on George Willard's wall: "I never had those feelings for you, George. It was all in your messed up brain."

Cohen is the author, most recently, of "Sweet and Low: A Family Story." His new book, "Israel Is Real: An Obsessive Quest to Understand the Jewish Nation and its History," will be out in August. [www.latimes.com]